D̄N interaction from meson-exchange and quark-gluon dynamics

We investigate the D̄N interaction at low energies using a meson-exchange model supplemented with a short-distance contribution from one-gluon-exchange. The model is developed in close analogy to the meson-exchange KN interaction of the Jülich group utilizing SU(4) symmetry constraints. The main ingredients of the interaction are provided by vector meson (ρ, ω) exchange and higher-order box diagrams involving D̄N , D̄∆, and D̄∆ intermediate states. The short range part is assumed to receive additional contributions from genuine quark-gluon processes. The predicted cross sections for D̄N for excess energies up to 150 MeV are of the same order of magnitude as those for KN but with average values of around 20 mb, roughly a factor two larger than for the latter system. It is found that the ω-exchange plays a very important role. Its interference pattern with the ρ-exchange, which is basically fixed by the assumed SU(4) symmetry, clearly determines the qualitative features of the D̄N interaction – very similiar to what happens also for the KN system. PACS. 14.40.Lb Charmed mesons – 12.39.Pn Potential models – 12.40.-y Other models for strong interactions – 13.75.Jz Kaon-baryon interactions